The present invention relates to an image forming apparatus such as an electrophotographic copying apparatus, a facsimile or the like, and more particularly to an image forming apparatus having a control function for controlling how often the apparatus is used per operator or per division in a company or the like.
There is known an electrophotographic copying apparatus having a control function (See, for example, Japanese Unexamined Patent Publication No. 134656/1983). According to a conventional apparatus having such a control function, a non-volatile memory has stored code data and the operator is prompted to enter code data with ten keys or the like, before making a copy with the apparatus. If the code data thus entered is not identical with one of the previously stored code data, the operator cannot use the apparatus. Accordingly, when different code data are respectively set and stored for a plurality of divisions of a company, an office or the like which commonly use the same apparatus, the number of copies made or the like per division may be controlled.
In such an apparatus having the control function, it is required to release, after use, the entered code data so as to prevent the apparatus from being freely used by other operators or divisions. The conventional apparatus has a special release button for releasing the entered code data.
A conventional electrostatic memory device having the control function requires a dedicated release button as above-mentioned. This results in an increase in the number of buttons or keys at the operation unit. This not only causes the arrangement of the operation unit to be complicated, but also increases the cost of the apparatus by an amount corresponding to such increase in the number of component elements.